Other potential complications include arrhythmia, tricuspid or pulmonic regurgitation, vascular access complications, including hematoma, pseudoaneurysm, or AV fistula, and anaphylactic reaction to iodine contrast. Bleeding may occur at any site from anticoagulation with intravenous unfractionated heparin. Renal failure may occur due to the use of iodine contrast for pulmonary angiography, particularly in patients with preexisting renal dysfunction.